Hi Gudrun, Let's see. First, the "cex" argument means character _expansion_, not an absolute size. So as the symbols and letters start out different sizes, that proportional difference remains as they are expanded. The size of text depends a bit upon the font that is being used. Perhaps if you determine the expansions necessary to get the "A" the same size as the pch=20 symbol (I get about two and one half times the expansion for the symbol as for the letter) you can write this into your code.
Margins are another unit, the number of lines (vertical space required for a line of text). This is somewhat larger than the actual vertical extent of the letters as there is a space left between lines. If you change the device (eg from PNG to PDF) you will probably encounter yet another change in the apparent size of things. I suggest using the eyeball method to work out the proportions for the device you want to use and be prepared to change things if you move to another graphics device. Jim On Tue, Nov 10, 2015 at 7:15 PM, Gygli, Gudrun <gudrun.gy...@wur.nl> wrote: > Dear R-help, > > > I am trying to plot some data in a plot where I leave a big margin free to > add other information, namely text and points. > > I am now struggling with keeping the size of the margin, text and points > in a fixed ratio. I want this so that the layout of the figure does not > change every time I plot new data. > > I have: > > a<-8 > counter<-1 > spacing<-a/(3*a) > adding<-a/(3*a) > start<-a*(a/3) > > alphabet<-c("A","A","A","A","A","A","A","A") > x<-c(1,2,3,4,5,6,7,8) > y<-c(10,20,30,40,50,60,70,80) > png(file="TESTING.png", units="in", width=a, height=a, res=a*100) > par(xpd=NA,mar=c(0,0,0,0),oma=c(0,0,0,(3*a))) #bottom, left,top, right > > plot.new() > plot(x,y) > points(pch=20,10, 10, cex=5) > text(10,10, alphabet, cex=5, col="blue") > > What I do not understand is why the size of the point and the text is not > the same and why the margin can be "bigger" than the width of the figure. > > BASICALLY, the units of the margins, the points and the text are not the > same... > > What I need is a way to make the size of the point and text AND the margin > independent of the data I plot so that the figure always looks the same > although there is more data in it in some cases (for example 10 or 20 > points with text in the margin). > > This could be done by setting the units of points, text and margin to > inches so that a is the same for all of them... Or to know the ratio > between the different units used by R for margin, points and text... > > Any ideas on how to solve that? > > Please let me know if clarifications are needed! > > > Gudrun > > > > > > > > Gudrun Gygli, MSc > > PhD candidate > > Wageningen University > Laboratory of Biochemistry > Dreijenlaan 3 > 6703 HA Wageningen > The Netherlands > > Phone 31 317483387 > e-mail: gudrun.gy...@wur.nl > > - - - - - - - - - - - - - - - - - - > > Project information: > http://www.wageningenur.nl/en/show/Bioinformatics-structural-biology-and-molecular-modeling-of-Vanillyl-Alcohol-Oxidases-VAOs.htm > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.